#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int main() {
    int n, i;
    scanf("%d", &n);
    int x = n * n - n + 1;
    for (i = 0; i < n - 1; i++) {
        printf("%d+", x + i * 2);
    }
    printf("%d", x + i * 2);
    return 0;
}


#include <stdio.h>

int main() {
    int n, sum = 0, a = 2;
    while (scanf("%d", &n) != EOF) {
        for (int i = 1; i <= n; i++) {
            sum += a;

            a += 3;

        }
        printf("%d", sum);
    }
    return 0;
}